UC-NRLF 


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ON 


CERTAIN   NEW   PHENOMENA 


CHEMISTRY, 


READ   BKFORE 


THE  ALBANY  INSTITUTE,  JAN.  2,  1872, 


VERPLANCK 


ON 


CERTAIN  NEW   PHENOMENA 


CHEMISTRY, 


BEAD  BEFORE 


THE  ALBANY  INSTITUTE,  JAN.  2,  1872, 


VEBPJLANCK  COJLVTtf. 
M 


1£>AN  STACK 

GIFT 


'hcnomcna  in  Chemist™. 


The  subject  of  this  paper  is  so  broad  and  varied,  the 
phenomena  so  interwoven  and  connected  with  different 
branches  of  material  science,  that  the  title  is  but  a  slight 
index  to  its  character,  and  the  paper  itself  can  be  only  a 
brief  statement  of  facts,  with  such  deductions  as  may  seem 
to  follow.  It  might  have  been  entitled  "  An  Account  of 
Mercury  and  its  Amalgams."  As  that,  however,  is  not 
exactly  the  scope  of  the  paper,  nor  the  final  object  of  it,  but 
only  the  means  or  vehicle  of  communicating  some  ideas — 
which  I  hope  will  prove  to  be  new — it  may  be  allowed  to 
stand  here  as  a  suggestions  to  the:  character  of  the  matter 
which  is  to  follow. 

With  the  discovery,  by  Humphry  Davy,  of  the  metals  of 
the  alkalies  and  earths,  a  new  era  opened  in  Chemistry. 
The  sombre  clouds  which  non-experimenting  theorists 
had  cast  around  the  science  were  suddenly  and  violently 
dissipated  in  the  blaze  of  simple  truth,  and  one  of  those 
epochs  occurred  which  must  from  time  to  time  recur,  as 
man  acquires  mastery  over  matter.  As  the  theories  of 
Stahl  and  his  phloyiston,  had  been  pressed  down  and 
swept  away  by  the  discoveries  of  the  previous  century,  so 
the  accumulated  errors  of  the  intervening  age  were  over- 
thrown by  Davy's  investigations,  and  the  new  metals  were 
evolved  by  electrolysis  in  the  form  of  amalgams  or  com- 
pounds with  mercury.  A  few  of  the  metals  of  the  earths, 
however,  could  not  be  thus  procured,  and  their  existence 
was  only  rendered  probable  by  the  analogous  action  of 


161 


4  New  Phenomena  in  Chemistry. 

their  salts  or  oxides  when  under  similar  treatment.  These 
discoveries  not  only  gave  to  Chemistry  a  list  of  new  metals, 
but  with  every  one  actually  evolved,  a  new  amalgam. 
Thus,  to  the  list  of  amalgams  known  to  the  ancients,  were 
added  numerous  new  compounds,  while  the  general  cha- 
racter of  the  elements  so  associated  was  of  the  most  dis- 
similar kind.  One  property  only  seems  peculiar  to  the 
majority  of  them,  softness  or  malleability,  and  ductility. 
To  this  class  of  easily  amalgamated  elements  belong  such 
old  metals  as  gold,  silver,  copper,  tin  and  lead ;  and  such 
new  metals  as  potassium,  sodium,  and  calcium. 

The  other  class  of  metals  is  peculiar  in  combining  but 
slightly  or  not  at  all  with  pure  mercury ;  and  these  metals, 
like  those  in  the  preceding  class,  seem  to  have  but  one 
general  characteristic,  the  reverse  of  that  of  the  first  class, 
hardness,  and  at  times,  even  brittleness. 

Iron,  probably,  alone  of  all  the  metals  known  to  the 
ancients,  belongs  to  this  second  class;  while  of  the  new 
metals  which  seem  to  belong  to  it,  chromium,  columbium, 
titanium,  manganese,  zirconium,  and  perhaps  rhodium  are 
examples.  Singularly  enough  platinum  and  aluminum, 
malleable  and  ductile  metals,  appear  to  be  attached  to  this 
class  by  reason  of  the  difficulty  experienced  in  directly 
combining  them  with  pure  mercury.  It  is  therefore 
plain  that  the  proper  classification  of  metals  as  regards 
their  affinity  for  mercury,  is  their  separation  into  these 
two  divisions ;  the  first  consisting  of  metals  that  readily 
combine  with  pure  mercury ;  the  second  consisting  of  metals 
which  refuse  to  combine  with  pure  mercury,  at  a  moderate 
temperature. 

One  of  the  consequences  of  the  discoveries  of  Hum- 
phry Davy,  was  the  application  of  the  amalgams  of  potas- 
sium and  sodium  to  purposes  of  exploration  in  Chemistry. 
Berzelius  and  Pontin  obtained  their  ammonium  amalgam 
by  the  direct  electrolysis  of  aqua-ammonia  in  contact  with 


New  Phenomena  in  Chemistry.  5 

mercury.  But  afterwards  it  was  observed  that  this  amalgam 
could  be  made  by  the  action  of  potassium  or  sodium 
amalgam  upon  chloride  of  ammonium.  It  has  been  stated 
that  the  amalgams  thus  procured  are  not  exactly  similar, 
the  amalgam  prepared  by  the  method  of  Berzelius  having 
a  composition  according  to  H.  Davy  of  one  part  of  ammo- 
nium to  753  of  mercury,  and  crystallizing  in  cubes  when 
cooled  to  zero  centigrade;  while  that  prepared  with  the 
aid  of  potassium  and  sodium  amalgam  contains  according 
to  Gay  Lussac  and  Thenard,  one  part  of  ammonium  to 
1800  parts  of  mercury. 

The  discovery  by  Graham  of  the  metallic  nature  of 
hydrogen  gas,  as  evinced  by  its  occlusion  in,  or  alloys  with 
palladium  and  platinum,  enables  us  to  avoid  the  difficulty  of 
believing  in  the  existence  of  a  metal  or  "  element  com- 
pounded of  gases  " — which  is  an  hibernicism — by  suppos- 
ing ammonia  to  be  an  alkaline,  nitrogen  salt  of  the  metal 
hydrogenium.  Then,  allowing  that  the  light,  cellular  or 
frothy  state  of  the  so  called  ammonium  amalgam  is  owing  to 
the  existence  throughout  the  mass  of  molecules  of  released 
nitrogen,  clinging  to,  and  recombining  with  the  rapidly  re- 
oxidizing  hydrogenium,  we  account  for  the  ammonical  gas 
afterward  given  off.  We  might  then  suppose  that  hydro- 
genium is  the  metal  of  the  volatile  alkali,  ammonia,  having 
little  resemblance  to  magnesium,  which  Graham  believed 
to  most  resemble  it.  This,  however,  is  only  an  hypothesis, 
and  is  indeed  a  digression. 

The  potassium  and  sodium  amalgams  enable  us  to  form, 
besides  this  hypothetical  amalgam,  compounds  of  mercury 
with  those  metals  which  I  have  arranged  in  a  second  class, 
as  refusing  to  combine  with  pure  mercury  at  a  moderate  or 
low  temperature.  The  process  is  simply  placing  potassium 
amalgam,  or  its  substitute,  excited  with  some  corrosive  gas, 
solution  of  a  salt,  aqua-ammonia,  water  or  acid  (as  the 
case  may  require)  in  contact  with  the  metals  to  be  amal- 


6  New  Phenomena  in  Chemistry. 

gamated.  A  triple  amalgam  of  mercury,  potassium  or 
sodium  and  "ammonium"  (hydrogenium  ?)  is  sometimes 
useful ;  and  I  have  found  zinc  amalgam,  excited  with 
chlorhydric  acid,  a  powerful  agent  in  producing  these  results. 

And  now,  before  proceeding  to  describe  those  pheno- 
mena of  the  discovery  of  which  I  can  find  no  record,  it  is 
advisable  to  examine  into  the  nature  of  mercury  and  its 
amalgams,  and  the  present  state  of  our  knowledge  of  its 
compounds. 

Remembering  that  the  fluid  mercury  with  which  we  are 
familiar  is  but  the  molten  substance  of  a  solid,  ductile 
and  malleable  metal;  we  arrive  at  the  conclusion  that 
amalgams  are  simply  the  alloys  of  mercury,  as  metals  dis- 
solved in  melted  lead  would  be  alloys  of  lead.  Now  the 
alloys  of  mercury  are  peculiarly  easy  to  examine ;  for  even 
when  in  the  fluid  state  they  do  not  burn  one's  fingers,  and 
by  analyzing  amalgams  we  are  able  to  discover  the  condi- 
tion of  the  metals  contained  in  them.  Having  prepared 
an  amalgam  of  gold  and  dissolved  it  in  an  excess  of  mer- 
cury, I  treated  the  fluid  amalgam  with  nitric  acid.  When 
the  quicksilver  had  entirely  dissolved,  there  remained  a 
small  spheroid  of  gold,  dark  upon  the  surface,  and  when 
broken  apart  under  the  hammer,  exhibiting  a  radiating 
crystallization  like  that  of  globular  iron  pyrites.  This,  and 
other  experiments  (which  I  have  not  time  to  describe), 
appear  to  prove  that  a  metal  when  amalgamated  is  really 
dissolved ;  and  it  is  possible  that  if  the  reduction  of  the 
amalgam  had  been  less  rapid,  a  well  formed  crystal  of 
gold  might  have  been  obtained.  The  metals  of  the  second 
class  seem  also  to  be  actually  dissolved  in  the  mercury. 

Our  knowledge  of  the  compounds  of  mercury,  as  de- 
rived from  the  latest  standard  works  on  Chemistry  is, 
singularly  imperfect.  St.  Glair  Deville,  the  famed  chemist 
of  the  late  French  empire,  the  discoverer  of  the  economic 
process  of  aluminum  manufacture,  asserts  that  metallic 


•        New  Phenomena  in  Chemistry.  7 

aluminum  is  not  susceptible  of  amalgamation.  Prof.  W. 
A.  Miller,  in  his  Inorganic  Chemistry  (3d  edition,  p.  425) 
also  says  of  aluminum  :  "It  does  not  combine  with  mer- 
cury." Yet  in  Watts's  Dictionary  of  Chemistry,  published 
in  London  three  years  previous  to  this  record  in  Miller, 
we  find  that,  "According  to  Caillettet  (Comp.  rend.,  44,  p. 
1250)  aluminum  (also  iron  and  platinum)  may  be  superfi- 
cially amalgamated  by  contact  with  ammonium  or  sodium 
amalgam  and  water;  also  when  immersed  in  acidulated 
water,  in  contact  with  metallic  mercury,  forming  the  nega- 
tive pole  of  a  voltaic  battery."  This,  published  in  London 
1865,  appears  to  ante-date  the  discovery  by  Pro£  Henry 
Wurtz  of  NQW^  York,  of  the  method  of  amalgamating 
aluminum  with  the  aid  of  sodium  amalgam  (Trans.  Am. 
Inst.  1867,  p.  766),  by  some  two  years ;  but  both  discoveries 
are  obviously  genuine.  Again,  both  Miller  and  "Watts 
Beem  not  to  be  aware  of  any  method  of  combining  mer- 
cury directly  with  metallic  platinum,  in  the  form  of  foil  or 
wire,  and  describe  an  indirect  method  of  obtaining  it, 
by  the  electrolysis  of  chloride  of  platinum.  Yet  potassium 
or  sodium  amalgam  will  readily  effect  the  combination. 
A  few  years  since,  while  experimenting  with  the  amalgams 
of  the  alkaline  metals,  I  observed  that  a  common  iron  nail 
which  happened  to  fall  into  the  amalgam,  became  coated 
with  mercury.  For  a  time  I  believed  myself  the  discoverer 
of  iron-amalgam,  but  on  examination  I  have  found  men- 
tion of  it  more  than  thirty  years  upon  record.  Aiken 
(London  Phil.  Mag.  xin,  p.  416).  shows  that  it  may  be 
accomplished  with  the  aid  of  zinc  amalgam  and  a  solution 
of  chloride  of  iron.  Watts  says  (1.  c.  vol.  in,  p.  887),  "  Mer- 
cury and  iron  do  not  unite  readily.  A  viscid  amalgam  is 
however  obtained  by  immersing  sodium  amalgam,  con- 
taining one  per  cent  of  sodium,  in  a  clear,  saturated  solution 
of  ferrous  sulphate.  Joule  (Chem.  Gaz.,  1859,  p.  839; 
Chem.  Soc.  J.,  xvi,  p.  378),  has  obtained  amalgam  of  iron 


8  New  Phenomena  in  Chemistry. 

by  electrolysis  of  a  solution  of  ferrous  sulphate,  the  nega- 
tive pole  heing  formed  of  mercury."  None  of  these  authors 
appear  to  be  aware  of  any  method  of  directly  amalgamating 
iron,  yet  H.  Davy  distinctly  states,  that  either  potassium 
or  sodium  amalgam  will  effect  the  union  of  mercury  with 
iron  and  platinum. 

Mercury  has  been  employed  from  time  immemorial, 
in  separating  the  precious  metals  from  their  earthy  asso- 
ciates. Originally  the  pure  metal  was  employed,  as  indeed 
it  still  is  to  a  considerable  extent,  held  in  little  rifts  or 
gutters  in  the  trough  or  sluice  where  they  washed  the 
auriferous  sands  or  pounded  ore.  This  was  also  the 
method  of  amalgamation  at  the  stamp-mills,  and  it  is 
notorious  that  much  gold  passed  over  the  mercury  in  this 
process,  and  escaped.  Recently  I  observed  in  the  gold 
mining  regions  of  the  Rocky  mountains,  at  Central  city  and 
Nevada,  Colorado,  that  for  the  rifts  and  gutters  filled 
with  mercury,  they  had  substituted  sheets  of  copper,  super- 
ficially amalgamated,  over  which  the  ore  reduced  to  a  thin 
mud,  or  muddy  water,  was  washed,  its  gold  parting  and 
adhering  to  the  surface  of  the  amalgamated  copper,  and 
doing  so  more  readily  than  it  would  to  the  surface  of  pure 
mercury. 

Here  we  have  another  instance  of  that  combination-action, 
which  we  have  already  noticed  in  the  potassium  and  sodium 
amalgams,  as  evinced  by  their  power  to  unite  mercury 
with  the  metals  of  the  second  class.  It  appears  that  those 
metals  of  the  first  class  which  are  softest,  lightest  and  most 
easily  oxidized  (as  potassium,  sodium,  zinc  etc.),  have  the 
power  to  enable  the  harder,  heavier  and  least  oxidizable 
metals  of  the  same  class  (as  copper,  silver  and  gold),  to 
combine  more  readily  with  mercury  than  they  would 
unassisted ;  and,  further,  to  enable  mercury  to  combine 
with  the  metals  of  the  second  class,  which  though  generally 


New  Phenomena  in  Chemistry.  9 

harder  and  more  brittle  than  any  of  the  preceding  are 
often  readily  oxidized.  This  combination-action  separates 
the  alloys  of  mercury  from  all  other  alloys,  so  far  as  we 
now  understand  them;  for,  as  I  have  already  shown, 
instead  of  the  mercury  always  losing  power  as  a  metal 
solvent  in  proportion  as  it  becomes  alloyed  —  it  shows  a 
preference,  —  and  when  combined  with  portions  of  the 
readily  oxidizable  metals,  becomes  more  active  and  indeed 
almost  ferocious  in  its  appetite  for  the  metals  and  alloys 
that  are  of  a  highly  electro-negative  character;  while  if 
alloyed  with  sufficient  gold  or  silver  in  the  first  instance,  it 
appears  satisfied,  phlegmatic  and  indifferent  to  further 
metallic  food.  Experiments  which  I  have  made  demon- 
strate that  cyanide  of  potassium  does  not  answer  as  well  as 
the  amalgams  of  the  alkaline  metals,  in  effecting  the  union 
of  mercury  with  electro-negative  metals,  as  some  have 
asserted.  Its  solution  is  indeed  not  more  effective  than 
aqua-ammonia  in  producing  such  results,  and  what  efficacy 
either  of  these  solutions  possess,  may  be  attributed  to  their 
cleansing  the  surface  of  the  metal  to  be  amalgamated. 

It  now  becomes  evident  that  the  separation  of  metals 
into  the  two  classes  is  incorrect,  as  we  have  here,  as  in 
every  other  general  classification  in  science,  no  absolute 
division,  but  merely  extremes  and  means;  the  true  mean 
being  difficult  to  determine.  The  reactions  of  these  amal- 
gams of  the  electro-positive  metals  with  those  metals 
which  are  relatively  electro-negative,  are  very  instructive. 
They  tend  to  prove  that  all  the  amalgams  subsequently 
formed  are  the  results  of  electrical  action,  to  induce  which 
we  have  only  to  place  a  particle  of  iron  in  contact  with 
potassium  amalgam  and  with  water.  In  an  instant  we 
have  a  voltaic  battery  in  active  operation;  the  amalga- 
mated potassium  forming  the  "zincode,"  while  the  iron  is 
the  electro-negative  element  of  the  battery.  Of  the  metals 
2 


10  New  Phenomena  in  Chemistry. 

present  the  mercury,  is  the  electromean,  and  with  the 
oxidation  of  the  potassium,  it  passes  over  to,  and  effects  a 
combination  with  the  iron. 

Thus  we  arrive  at  a  more  correct  classification,  and  at  a 
law  of  preference  of  metals  and  alloys  for  mercury : 

1st  Law.  Metals  that  are  easily  alloyed  with  mercury 
give  place  to,  and  assist  the  less  amalgamatable  metals  in 
combining  with  mercury,  when  in  the  presence  of  an 
acid  or  corrosive  liquid  or  atmosphere,  which  attacks  the 
metal  already  amalgamated,  and  which  does  not  attack, 
or  does  not  so  violently  attack  the  metal  to  be  amalga- 
mated. 

2d  Law.  The  more  intense  the  action  of  the  acid  or 
corrosive  liquid  or  gas  upon  the  metal  in  the  original 
amalgam,  the  more  rapid  the  formation  of  the  secondary 
amalgam. 

3d  Law.  The  amalgams  of  electro-positive  metals, 
assist  those  metals  which  are  relatively  electro-negative  in 
combining  with  mercury. 

These  laws  are  the  results  of  certain  experiments  which, 
as  examples,  I  will  now  proceed  to  describe  and  illustrate. 
Placing  before  us  mercury  1st,  in  the  pure  state;  2d 
amalgamated  with  copper;  3d  zinc  amalgam;  4th  aluminum 
amalgam ;  5th  sodium  amalgam  ;  6th  potassium  amalgam 
and  7th  "ammonium  amalgam " (by drogenium ?)  we  may 
suppose  that  we  have  the  extremes  and  some  of  the  means 
of  mercurial  power ;  mercury  in  the  pure  passive,  and  in 
the  compound  induced  active  state.  To  prove  that  it  has  a 
passive  and  an  active  condition,  it  is  only  necessary  to 
exhibit  gold  leaf  before  the  pure  mercury,  and  each  of  the 
several  compounds  mentioned. 

First.  It  will  be  seen  that  with  mercury  alone  it  does 
not  readily  amalgamate,  and  there  is  no  attraction  of  the 
gold  leaf  toward  the  metal. 


New  Phenomena  in  Chemistry.  11 

Second.  Held  above  the  amalgamated  copper  there  is 
no  attraction,  hut  the  moment  the  gold  is  allowed  to  touch 
the  surface,  it  is  eagerly  seized  and  devoured. 

Third.  Held  above  zinc  amalgam  excited  with  chlor- 
hjdric  acid,  the  gold  leaf  begins  to  waver  and  tremble 
slightly  as  though  influenced  by  the  amalgam.  Touched 
to  the  amalgam  it  is  seized  and  vanishes  instantly. 

Fourth.  Above  the  sodium  amalgam,  excited  with  water 
or  aqua-ammonia,  we  have  the  same  symptoms,  but  even 
more  excitement  and  eagerness  on  the  part  of  the  gold 
leaf  to  pass  to  the  amalgam  as  it  is  approached ;  and  the 
gold  is  scarcely  touched  ere  it  is  gone,  licked  up  by  the 
hungry  amalgam. 

[This  action  is  only  seen  when  but  short  distances  inter- 
vene between  the  gold  leaf  and  amalgam,  an  eighth  or 
sixteenth  of  an  inch.  To  perform  the  experiment  success- 
fully, the  water  should  just  cover  the  amalgam,  and  the 
edge  of  the  gold  leaf  should  be  allowed  to  dip  a  little  into 
the  water.] 

Fifth.  With  potassium  amalgam  the  action  is  greater. 

Sixth.  With  the  hypothetical  hydrogenium  or  ammonium 
amalgam,  I  have  found  less  action  than  the  supposedly 
high  electro-positive  character  of  the  metal  (?)  would  indi- 
cate. This  might  be  accounted  for  by  the  porous  condi- 
tion of  the  amalgam,  owing  to  the  gas  contained  (nitrogen  ?) 
and  consequently  much  diffused  state  of  the  "  metal."  I 
notice  this  last  experiment  and  reaction,  merely  because  it 
may  be  valuable  in  determining  whether  such  gaseous 
metals  exist. 

The  result  here  seems  to  be  that  we  have  now  for  the 
first  time,  a  metallic  compound  capable  of  attracting  the 
precious  metal  gold,  when  but  a  short  distance  intervenes. 
We  can  amuse  ourselves  with  the  idea  that  upon  this 
principle  a  compass  may  be  constructed  (a  tube  charged 
with  the  amalgam),  which  will  be  to  the  prospector  and 


12  New  Phenomena  in  Chemistry. 

gold  hunter  as  the  magnetic  dip  needle  is  to  the  searcher 
after  iron  ore.  Still,  there  is  something  inexplicable  about 
it,  for  this  apparent  attraction  of  gold  can  hardly  be  mag- 
netic, and  it  seems  to  me  we  must  look  for  explanation 
to  cohesive,  molecular  power. 

I  have  shown  that  the  combination  of  mercury  and  iron 
was  long  since  effected ;  I  have  now  to  claim  as  a  dis- 
covery the  direct  amalgamation  of  steel,  even  when  of  the 
toughest  and  hardest  character.  The  blade  of  the  best 
pen  knife  is  readily  amalgamated,  and  suffers  from  the 
contact,  while  a  plate  of  fine  sheet  steel,  used  in  the 
manufacture  of  superior  instruments,  is  easily  coated  with 
mercury  and  made  to  resemble  a  sheet  of  silver.  By  mag- 
netizing soft  steel,  reducing  a  sufficient  amount  of  it  to 
filings,  and  dissolving  the  filings  in  mercury,  I  have  pro- 
cured a  magnetic  amalgam,  in  the  presence  of  which  an 
astatic  needle  is  decidedly  bewildered.  The  horseshoe 
magnet  which  has  this  evening  been  exhibited  brightly 
coated  with  and  upholding  an  inverted  arch  of  fluid, 
dripping  mercury,  lifts  quicksilver,  it  is  true,  but  quicksilver 
loaded  with  an  amalgam  of  magnetized  steel ;  an  attraction 
much  stronger  than  that  evinced  for  iron  amalgam. 

A  glass  tube  properly  charged  with  the  magnetic  amal- 
gam exhibits  the  polarity  of  the  compass  needle,  and  has 
its  extremities  attracted  and  repelled  by  the  poles  of  the 
magnet  in  the  same  manner  that  the  poles  of  the 
compass  needle  are  attracted  and  repelled.  This  property 
of  the  magnetic  amalgam  is  interesting,  as  it  proves  that 
however  minutely  divided,  the  atoms  of  steel  still  retain 
their  magnetism,  and  are  still  influenced  by  the  directive 
currents  of  the  earth.  I  have  not  yet  been  able  to  make 
a  very  powerful  needle  of  this  kind;  but,  though  my  obser- 
vations are  very  imperfect,  am  able  to  say  that  it  seems  to 
point  a  little  more  truly  to  the  magnetic  north,  and  from 
its  greater  inertia  to  be  less  subject  to  irregular  changes 


Phenomena  in  Chemistry.  13 

of  variation  than  the  ordinary  compass  needle.  The 
inertia  is  to  be  attributed  to  the  assumption  by  the 
magnetized  steel  of  a  certain  portion  of  the  weight  or 
specific  gravity  of  the  mercury.  "When  this  amalgam  is 
exposed  to  the  oxidizing  influence  of  the  atmosphere,  it  is 
gradually  decomposed,  carbon  being  liberated,  and  the 
permanent  magnetism  vanishing,  while  iron  amalgam  re- 
mains. This  will  also  finally  decompose,  pure  mercury 
and  ferrous  oxide  resulting. 

Another  discovery  that  I  may  claim,  is  the  direct  amal- 
gamation of  cast-iron,  even  of  the  most  brittle  and  highly 
carburetted  character.  This  was  first  effected  by  means  of 
a  compound  amalgam  of  potassium,  sodium  and  "ammo- 
nium "  with  water;  but  I  have  since  found  that  a  simple 
amalgam  of  potassium  or  sodium  is  generally  sufficient  to 
effect  the  result.  The  surface  of  cast-iron  may  be  amal- 
gamated by  placing  an  electro-positive  or  active  amalgam 
upon  it  with  water  or  an  acid ;  a  true  amalgam  may  be 
similarly  formed  with  filings. 

In  the  course  of  the  experiments  which  led  to  this  dis- 
covery, it  was  my  fortune  to  observe  phenomena  of  an 
extraordinary  character.  The  usual  brilliant  surface  of 
mercury  is  produced  when  cast-iron  is  treated  with  the 
electro-positive  amalgam,  and  the  iron  is  rapidly  "  cut  "  or 
dissolved.  The  impurities  of  the  iron,  with  considerable 
carbon  are  released  and  form  a  black  mud  around  the 
button  of  amalgam.  If  at  this  moment,  before  all  the 
positive  metal  has  been  oxidized,  the  amalgam  be  removed, 
washed  and  allowed  to  stand,  particles  of  amorphous 
carbon  will  be  seen  to  emerge  and  float  upon  its  mirror-like 
surface.  Whence  comes  this  carbon ;  why  was  it  not  given 
up  before  ?  Has  it  been  amalgamated ;  and  if  so,  has  it  not 
a  metallic  character  ?  It  has  been  suggested  to  me  that 
particles  of  undissolved  iron,  containing  carbon,  have 
been  carried  bodily  into  the  amalgam,  and  afterwards  dis- 


14  New  Phenomena  in  Chemistry. 

solved,  releasing  their  carbon.  However,  this  is  but  a  con- 
jecture ;  the  reaction  certainly  deserves  study. 

The  mere  intimation  that  carbon,  the  great  protean 
thing  in  nature,  may  after  all  have  a  metallic  origin,  is 
very  interesting.  Those  who  believe  in  the  ammonium  of 
Berzelius  or  the  hydrogenium  of  Graham,  need  not  fear 
to  examine  the  claims  of  carbon  to  a  metallic  parentage,  nor 
does  the  existence  of  such  a  metal  seem  so  improbable 
when  we  remember  the  electric  cooductibility  of  two  of  the 
allotropie  forms  of  carbon,  gas-coke  and  plumbago;  the 
first  already  replacing,  in  the  voltaic  batteries  of  the  pre- 
sent day,  the  electro-negative  elements,  platinum,  copper 
etc.,  while  the  latter  replaces  similar  electro-negative  ele- 
ments when  brushed,  in  the  form  of  plumbago  powder, 
upon  the  surface  of  the  mould  or  plaster-cast  which  the 
electro-plater  desires  to  coat  with  copper  or  other  metal. 

If  metallic  carbonium  exists,  it  may  be  assumed  to  be  an 
electro-negative  metal.  It  is  true  that  some  forms  of 
carbon  are  highly  inflammable,  but  are  they  more  so  than 
Graham's  hydrogenium?  Graphite  at  ordinary  tempera- 
tures is  far  from  combustible,  and  when  it  burns,  or  when 
the  diamond  burns  in  oxygen  gas,  wrought  iron  will  burn 
also.  No  one  doubts  that  iron  is  a  metal,  yet  one  of  its 
purest  forms  is  pyrophoric,  taking  fire  and  burning  on 
contact  with  the  atmosphere.  To  associate  graphite  with 
sulphur  and  phosphorus  is  to  place  it,  a  good  conductor  of 
electricity,  side  by  side  with  the  very  enemies  of  traveling 
magnetism.  For  how  many  ages  was  molybdenite  undis- 
tinguished from  graphite,  and  who  is  there  now  that  can 
instantly  distinguish  the  one  from  the  other?  It  is 
true  that  molybdenite  is  a  sulphide  of  molybdenum  and 
graphite  a  pure  allotfopic  form  of  carbon,  but  may  there 
not  be  one  more  form  of  carbon  ?  There  is  no  sub- 
stance in  nature  more  readily  recognized  as  a  metal  by  the 
unlearned  than  graphite;  to  this  day  it  is  impossible  to 


New  Phenomena  in  Chemistry.  15 

take  from  it  the  improper  title  of  black-lead.  The  experi- 
ments of  Sir  Benjamin  Brodie  with  graphite,  his  discovery 
of  graphic  acid  and  its  combination  with  ammonia 
(graphate  of  ammonia  f)  afford  another  analogy ;  for  molyb- 
denum has  its  molybdic  acid,  and  what  chemist  is  there 
that  is  not  familiar  with  molybdate  of  ammonia.  I  have 
found  that  contact  of  native  graphite  with  an  electro-posi- 
tive amalgam  and  water  or  acid,  produces  the  same  reac- 
tion and  effervescence,  as  when  a  negative  metal  occupied 
the  place,  but  an  amalgam  did  not  seem  to  form. 

It  would  appear  that  the  division  of  elements  into  metals 
and  non-metals,  is  as  arbitrary  as  any  other  absolute  divi- 
sion or  classification  in  science ;  for  though  the  extremes 
may  readily  be  distinguished,  —  as  gold  from  fluorine, — 
the  means  often  approach  each  other  in  appearance  and  in 
properties. 

Besides  forming  amalgams  of  steel  and  cast-iron,  I  have 
succeeded  in  combining  mercury  directly  with  crystalline 
octahedral  iron  ore  (magnetite),  and  with  other  ores  and 
some  furnace  products.  The  loadstone  exhibited,  coated 
with  mercury,  is  from  the  Adirondack  mountains.  Red 
fossiliferous  hematite  ore  from  Georgia  is  also  readily 
amalgamated.  Bog-iron  has  so  far  resisted  mercury,  save 
one  specimen  from  the  state  of  Florida,  which  appeared  to 
receive  it  slightly.  The  slag,  etc.,  of  the  Colorado  gold- 
smelting  furnaces  may  also,  by  means  of  the  compound 
amalgam,  be  coated  with  mercury.  Magnesium  may  be 
amalgamated  with  the  aid  of  zinc-amalgam  and  chlor- 
hydric  acid ;  much  heat  is  evolved,  sufficient  indeed  to  burn 
the  hand  if  laid  upon  it.  Bi-sulphide  of  carbon,  treated 
with  the  compound  amalgam,  is  decomposed;  sulphides 
of  the  alkaline  metals  result,  while  another  portion  of 
sulphur  combines  with  the  mercury,  forming  true  ver- 
milion. Carbon  separates  in  form  resembling  graphite. 


16  New  Phenomena  in  Chemistry. 

The  practical  applications  of  these  discoveries  are  numer- 
ous. As  mercury  dissolves  iron  and  its  ores,  and  finally 
separates  the  metal  from  its  impurities  of  silicon,  sulphur 
and  phosphorus,  it  may  prove  possible  to  prepare  an  iron, 
nearly  as  pure  as  that  reduced  by  hydrogen,  for  medicinal 
purposes,  by  distilling  the  mercury  from  the  amalgam.  In 
accordance  with  the  laws  announced,  it  is  evident  that 
plates  of  amalgamated  zinc  or  iron  are  superior  to  plates 
of  copper  in  effecting  the  amalgamation  of  gold,  especially 
if  they  be  treated  with  proper  acid  solutions  while  the 
stamped  ore  is  being  run  out  over  them.  Potassium  and 
sodium  amalgams  are  undoubtedly  more  effective,  but  can 
hardly  compete  with  amalgamated  zinc-plates  in  cheapness. 

A  great  philosopher  has  said  that  the  results  of  all  experi- 
ments should  be  recorded,  nothing  being  worthless  that 
adds  to  man's  knowledge  of  the  properties  of  matter.  It 
is  my  hope  that  the  experiments  described,  and  sugges- 
tions here  thrown  out,  may  not  be  altogether  valueless. 


